title: Photoinduced electron transfer modeling to simulate flavoprotein fluorescence decay.
abstract: A method of analysis is described on the photoinduced electron transfer (PET) from aromatic amino acids as tryptophans (Trp) and tyrosines (Tyr) to the excited isoalloxazine (Iso*) in FMN-binding proteins (FBP) from Desulfovibrio vulgaris (strain, Miyazaki F). Time-dependent geometrical factors as the donor-acceptor distances are determined by means of a molecular dynamics simulation (MDS) of the proteins. Fluorescence decays of the single mutated isoforms of FBP are used as experimental data. The electrostatic (ES) energy between the photoproducts and ionic groups in the proteins is introduced into the Kakitani and Mataga (KM) model, which is modeled for an electron transfer process in solution. The PET parameters contained in the KM rate are determined by means of a nonlinear least square method, according to the Marquardt algorithm. The agreement between the observed and calculated decays is quite good, but not optimal. Characteristics on PET in flavoproteins, obtained by the present method, are described. Possible improvements of the method are discussed.
authors.affiliation: Faculty of Science, Department of Chemistry, Mahasarakham University, Mahasarakham, Thailand.
authors.forename: Nadtanet
authors.initials: N
authors.lastname: Nunthaboot
authors.forename: Kiattisak
authors.initials: K
authors.lastname: Lugsanangarm
authors.forename: Arthit
authors.initials: A
authors.lastname: Nueangaudom
authors.forename: Somsak
authors.initials: S
authors.lastname: Pianwanit
authors.forename: Sirirat
authors.initials: S
authors.lastname: Kokpol
authors.forename: Fumio
authors.initials: F
authors.lastname: Tanaka
mesh_terms: D002352:Carrier Proteins / Q000737:chemistry; D016969:Desulfovibrio vulgaris / Q000737:chemistry; D044927:Electron-Transferring Flavoproteins / Q000737:chemistry*; D005486:Flavin Mononucleotide / Q000737:chemistry; D005453:Fluorescence; D056004:Molecular Dynamics Simulation; D010777:Photochemistry / Q000379:methods; D012996:Solutions / Q000737:chemistry; D014364:Tryptophan / Q000737:chemistry*; D014443:Tyrosine / Q000737:chemistry
chemical_list: D002352:Carrier Proteins; D044927:Electron-Transferring Flavoproteins; D012996:Solutions; D014443:Tyrosine; D005486:Flavin Mononucleotide; D014364:Tryptophan